1. Field of the Invention
The present invention relates to a method of altering the phenotype of cells expressing an oncogene by expressing a nucleic acid encoding interferon regulatory factor 1 (IRF-1).
2. Background Information
Interferon regulatory factor-1 (IRF-1), a transcriptional activator, and IRF-2, its antagonistic repressor, have been identified as regulators of type I interferon (IFN) and IFN-inducible genes. It has been shown previously that IRF-1 manifests anti-oncogenic activity in NIH 3T3 cells which are transformed with IRF-2, a natural antagonist of IRF-1. When the IRF2 gene was overexpressed in NIH 3T3 cells, the cells displayed enhanced tumorigenicity in nude mice. However, this phenotype was reversed by concomitant overexpression of the IRF-1 gene (Harada et al., Science259: 971-974 (1993)). It has been shown that the human IRF-1 gene maps to chromosome 5q31.1, a region frequently deleted in patients with leukemia or preleukemic myelodysplastic syndromes (Willman et al., Science 259: 968-971 (1993)).